PSMDB-1078: fix TemporaryRecordStoreSimple test to handle ObjectIsBusy from dropIdent

The TemporaryRecordStoreSimple test can fail when dropIdent() returns
ErrorCodes::ObjectIsBusy, which occurs when the ident is temporarily in
use. This is a transient condition that should be retried.

This change adds retry logic to the test, retrying dropIdent() until it
succeeds when ObjectIsBusy is returned. This matches the pattern used in
production code (e.g. WiredTigerKVEngine::dropIdentForImport).

Author: plebioda

src/mongo/db/storage/kv/kv_engine_test_harness.cpp

@@ -389,7 +389,14 @@ TEST_F(KVEngineTestHarness, TemporaryRecordStoreSimple) {
         engine->checkpoint();
 
         WriteUnitOfWork wuow(opCtx.get());
-        ASSERT_OK(engine->dropIdent(shard_role_details::getRecoveryUnit(opCtx.get()), ident));
+
+        // Drop the temporary record store in a loop in case it returns ErrorCodes::ObjectIsBusy
+        Status status = Status::OK();
+        do {
+            status = engine->dropIdent(shard_role_details::getRecoveryUnit(opCtx.get()), ident);
+            ASSERT(status.isOK() || status == ErrorCodes::ObjectIsBusy);
+        } while (status == ErrorCodes::ObjectIsBusy);
+
         wuow.commit();
     }
 }